> 
> # 3. Fit a particular model
> # This is a model with S constant over time (closest to Mayfield method)
> mod.baf <-  RMark::mark(red.baf.proc, ddl=red.baf.ddl,
+                           model="Nest",
+                           model.parameters=list(
+                             S   =list(formula=~1)
+                           )
+   )
Error in t(age.mat) + cumsum(c(0, time.intervals[1:(nocc - 2)])) : 
  non-numeric argument to binary operator
In addition: Warning message:
Unknown or uninitialised column: 'ch'. 
Error in RMark::mark(red.baf.proc, ddl = red.baf.ddl, model = "Nest",  : 
  Misspecification of model or internal error in code
> summary(mod.baf)
Error in summary(mod.baf) : object 'mod.baf' not found
>